Final answer:
Cells that have 1.5 times more DNA than those in the G1 phase are in the S phase of the cell cycle, where DNA replication is in progress.
Step-by-step explanation:
The student's question relates to determining the phase of the cell cycle that cells are in if they have 1.5 times more DNA than G1 phase cells.
The key to answering this question lies in understanding the stages of the cell cycle, particularly the stages of interphase, during which the cell's DNA content changes.
In the G1 phase, cells have a normal amount of DNA. Following G1 is the S phase (synthesis phase), which is characterized by DNA replication. By the end of S phase, the DNA content of a cell has doubled.
Therefore, cells that have 1.5 times more DNA are currently in the S phase, where DNA replication is partially complete.